A method for adding labels to data, for example XML compliant or XBRL compliant labels, includes a) identifying data in an electronically represented file, b) selecting labels that correspond to text strings in the identified data, based on a list associating labels with text strings, and c) adding the selected labels into the electronically represented file to label the text strings and elements in the identified data associated with the text strings. The labels include information about the data and are defined in one or more taxonomies. When the list does not associate a label with the text string, a user can be prompted to select a label corresponding to a text string in the identified data. The association indicated by the user's selection, can then be added to the list associating labels with text strings.